AMERICAN WATER WORKS ASSOCIATION
NEW JERSEY SECTION
2015 Annual Conference
So Many Pipes to Inspect –
So Which One’s First?
Brian F. Carr, P.E.
Middlesex Water Company
David J. Tanzi, P.E., BCEE
CDM Smith Inc.
March 19, 2015
Agenda
• Introduction
• Classic prioritization process
• Risk-based prioritization approach
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Probability of failure
Prioritization process
Scoring
CapPlan
Results
Methods of condition assessment
Development of capital plan
Conclusions
Questions
So Many Pipes to Inspect – So Which One’s First?
Middlesex Water Company –
Background
• 118-year-old, NASDAQ-listed
company
• Provides water, wastewater,
and related utility services in
central New Jersey and
Delaware
• Serves a population of more
than 400,000
• ~40 miles of trunk mains
• ~700 miles of distribution main
So Many Pipes to Inspect – So Which One’s First?
Middlesex Water Company –
Background
• Already embarked on a 20 year plan
• $50M over that time in pipe renewal
• Average of 5.8 miles of small
diameter main renewed each year
• Focus attention on large diameter mains
• Unsure of:
– Type of condition assessment to perform
– What and when to inspect
• Needed to develop a long-range,
risk-based plan
• Desired a condition assessment program to:
– Manage it over time as needs change
– Assist in capital budget planning
So Many Pipes to Inspect – So Which One’s First?
30-inch and Greater Diameter
PCCP Transmission Mains
• 70,500 LF of 30-inch installed
between 1949 and 1990
• 11,600 LF of 36-inch installed
between 1965 and 1969
• 19,000 LF of 42-inch installed
in 1990
• 24,500 LF of 48-inch installed
between 1965 and 1969
So Many Pipes to Inspect – So Which One’s First?
CLASSIC PRIORITIZATION PROCESS
Triage For Water Main Condition Assessment
• Merriam Webster Defines Triage: the assigning of priority
order to projects on the basis of where funds and other
resources can be best used, are most needed, or are most
likely to achieve success
Highest Ranked
Assets Based on
Risk
High Risk Assets
with Uncertain
Condition or Limits
So Many Pipes to Inspect – So Which One’s First?
Survey Level
CA
Advanced
CA
Classic Process for Prioritization
• Requires assumptions
– Service life of assets
– Which factors affect asset life and by how much?
• Linear process
Assumptions
Capital Plans
– Limited feedback
– Minimal guidance on future data collection
• Not integrated into the enterprise
– Lack of dedicated capital planning software
Information
Collection
Processing
Tools
So Many Pipes to Inspect – So Which One’s First?
Outputs
Classic Tools for Prioritization
• Legacy employees
– People with vast knowledge of the system and where the
problems are
• Paper mapping, or individual systems
– Replace based on age or individual statistics
– Tracking of main breaks
– Customer complaints
• These are not sustainable and not integrated into the
enterprise
– Lack of feedback and not detailed capital planning
So Many Pipes to Inspect – So Which One’s First?
Defensible Capital Planning Framework
• Change in capital planning direction
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Easy work has been done – now what?
Where does a system stand in its “asset life”?
How much do we need to replace?
How do we reduce consequence of failure over time?
Leverage GIS and hydraulic model investment
• What are the tools to support this?
• Goals:
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Asset inventory
Prioritization of the inventory
Defensible
Plan for inspection
So Many Pipes to Inspect – So Which One’s First?
RISK-BASED PRIORITIZATION APPROACH
New Tools for Prioritization – A Good Base
Hydraulic Model
Computerized Maintenance
Management Systems (CMMS)
So Many Pipes to Inspect – So Which One’s First?
Microsoft Excel
Geographic
Information
Systems (GIS)
The Long-Term, Risk-Based Approach
• Capital planning process is no longer linear
– Building upon GIS, hydraulic models, etc.
GIS Data
– Continuous feedback
• Includes:
Anecdotal Data
Hydraulic Model
– Long-term budget
Field Samples
needs analysis
O&M Data
– Ranking assets
for renewal based
on risk
– Electronic decision Decision
Support
support tools
Tools
Capital Plan
So Many Pipes to Inspect – So Which One’s First?
KANEW
LEYP
Defensible &
Sustainable
Capital
Planning
Innovyze
CapPlan
GIS Processing
Probability of Failure
RISK-BASED PRIORITIZATION APPROACH
Risk-Based Asset Ranking Factors for MWCo
• Probability of failure
• Consequence of failure
• Multiple workshops with project stakeholders
– Engineering
– Distribution
– Operations
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Dependent on existing data
Analysis fed by GIS and model
Defensible
Industry driven
So Many Pipes to Inspect – So Which One’s First?
Probability of Failure Factors - Initial
Bury depth
Earthquake / earth shift
Electrical transmission lines
Joint types
Type of lining
Major roadways
Manufacturing issues
Model C-Value –
proxy for condition
• Number of connections
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So Many Pipes to Inspect – So Which One’s First?
• Past breaks/leaks/service
history issues
• Pipe age or vintage
• Pipe wrapping
• Pressure
• Pressure fluctuation
• Railway crossing
• Soil resistivity
• Water age
• Water hammer/transients
Data Sources
• MWCo GIS database
– Location of valves, blow-offs, AVRV’s
• As-built drawings
– Plan and profile
• Cut-sheets
– PCCP design criteria
• Hydraulic model
– Historical, current and future operating pressures
• Soil types
– MWCo known issues
• Known pipeline issues
– Past break locations
So Many Pipes to Inspect – So Which One’s First?
Probability of Failure Factors - Removed
• Earthquake / earth shift
– Lack of applicability
• Type of lining
– All pipe has CML
• Model C-Value - proxy for
condition
– C-values did not vary
significantly
So Many Pipes to Inspect – So Which One’s First?
• Pipe wrapping
– Lack of information
• Water age
– Not significant variation
Probability of Failure Factors - Final
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Bury depth
Electrical transmission lines
Joint types
Major roadways
Manufacturing issues
Number of connections
So Many Pipes to Inspect – So Which One’s First?
• Past breaks/leaks/service
history issues
• Pipe age or vintage
• Pressure
• Pressure fluctuation
• Railway crossing
• Soil resistivity
• Water
hammer/transients
Prioritization Process
RISK-BASED PRIORITIZATION APPROACH
Overview of Prioritization Process
• Weighting values
– 1 (negligible) to 5 (extreme)
– Table 2-2 per kickoff workshop
• Scoring ranges
– Range of scores developed for each factor: 0 (lowest)
to 5 (highest)
– Applied to differentiate scores based on severity
– Developed by Project Team
• Exponent
– Exponential factors can be used to increase the score of
specific factors
– No exponents were applied (value set to 1)
So Many Pipes to Inspect – So Which One’s First?
Scoring
RISK-BASED PRIORITIZATION APPROACH
Failure Risk Factor: Joint Types
Factor Description
Factor
Weighting
Value
Factor Scoring Range
Bolted Bell (5)
Certain joint types are more
susceptible to failure than other
joint types.
Welded (3)
2
Harnessed (2)
Restrained (2)
Bell and Spigot/Unknown (0)
So Many Pipes to Inspect – So Which One’s First?
Failure Risk Factor:
Joint Types
• Source:
– Record drawings and lay
schedules
– MWCo GIS database
• Data processing methodology
– Known restrained joint types
receive a higher score for
potential failure.
– Unknown joint types and
unrestrained bell and spigot
joints receive a lower score
for potential failure.
So Many Pipes to Inspect – So Which One’s First?
Failure Risk Factor: Major Roadways
Factor Description
Factor
Weighting
Value
Larger, more traveled roadways
generally have more salt applied
to them and have more traffic
load causing potential pipe
corrosion or harm. Major
roadways are defined as US
Route, Interstate, Toll Route,
Ramp, State and County
roadways.
So Many Pipes to Inspect – So Which One’s First?
1
Factor Scoring Range
Within 40-ft of
Major Roadway (5)
Not Within 40-ft of
Major Roadway (0)
Failure Risk Factor:
Major Roadways
• Source:
– MWCo GIS database
• Data processing methodology
– Pipes that cross over or run
parallel to major streets
– 40 feet buffer on either side
of centerline of major street
– Pipes within buffer receive a
higher score for potential
failure
So Many Pipes to Inspect – So Which One’s First?
Failure Risk Factor: Pressure Fluctuation
Factor Description
Factor
Weighting
Value
Factor Scoring Range
Fluctuations Greater than
16 psi (5)
Large, daily average pressure
fluctuations in a pipeline can
weaken a pipe over time.
Fluctuations 12 to 16 psi (4)
3.5
Fluctuations 9 to 12 psi (3)
Fluctuations 2 to 9 psi (2)
Fluctuations less than 2 psi (0)
So Many Pipes to Inspect – So Which One’s First?
Failure Risk Factor:
Pressure Fluctuation
• Source:
– MWCo hydraulic model
• Data processing methodology
– Pipe segments with larger
fluctuations in pressure
receive a higher score for
potential failure due to the
potential for large, daily
average pressure fluctuations
to weaken a pipe over time.
So Many Pipes to Inspect – So Which One’s First?
CapPlan
RISK-BASED PRIORITIZATION APPROACH
Leveraging CapPlan: Setting up
the Condition Factors
• Software reads GIS and modeling data
• Build tests based on spatial analysis,
physical attributes, failure history, etc.
• Easy to use interface
– Select type of test
– Select attributes to rank on
– Can select model scenario
to run
So Many Pipes to Inspect – So Which One’s First?
Results
RISK-BASED PRIORITIZATION APPROACH
Probability of Failure Analysis Results
So Many Pipes to Inspect – So Which One’s First?
Probability of Failure Analysis Results
• Total aggregate
probability of failure
score for each PCCP
segment
• Scores ranged from
25 to 109
• Red: high probability
• Dark Blue: low
probability
So Many Pipes to Inspect – So Which One’s First?
METHODS FOR CONDITION ASSESSMENTS
Methods for Condition Assessments
Pipe Condition Assessment Technologies
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Electromagnetics (EM) testing
Internal visual inspection (CCTV)
Sonar and laser scanning inspection
Sonic/ultrasonic/impact echo testing
Acoustic pulse testing
Pipe wall soundings and wire investigation
External inspection with soil and groundwater testing
Coupons or sampling
Air Release Valve (ARV) inspection
So Many Pipes to Inspect – So Which One’s First?
Condition Assessment Toolbox
This image cannot currently be display ed.
So Many Pipes to Inspect – So Which One’s First?
Methods for Condition Assessments
Pipe Out of Service Assessment
Methods
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Electromagnetics testing
Internal visual inspection
Sonic/ultrasonic/impact echo testing
Coupons or sampling
Leak Detection Technologies
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Internal visual inspection with
hydrophone
Free swimming acoustic leak
detection
Acoustic pulse testing
Thermography
Ground penetrating radar
So Many Pipes to Inspect – So Which One’s First?
Pipe In Service Assessment
Methods
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Electromagnetics testing
Internal visual inspection
Sonic/ultrasonic testing/
impact echo
Acoustic pulse testing
Pipe wall soundings and wire
investigation
Soil and groundwater testing
Air release valve inspection
Long-Term Continuous
Monitoring Technologies
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Acoustic fiber optics
Wireless acoustic monitoring
Electromagnetic (EM) Testing
Detect wire breaks and large areas of corrosion
Can be conducted on in service or out of service pipe
Excavation required if access is not available
Can be a manned, robotic, or free
swimming inspection
• Manned inspections for pipe
diameters greater than 36-inch
• Assessment of prestressing wires
which is used to evaluate failure risk
• Combine with internal visual
inspection, pipe wall soundings
and wire investigation for when
pipe out of service
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So Many Pipes to Inspect – So Which One’s First?
Internal Visual Inspection (CCTV) on Live Mains
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Conducted on in-service pipe
Excavation only required if 2-inch tap is not available
Travels at 80% to 90% the flow rate
Limited by bends and butterfly valves
Cracking and leak detection
Tethered so less prone to getting stuck
The Sahara System (Courtesy of Pure Technologies)
So Many Pipes to Inspect – So Which One’s First?
Sonic/Ultrasonic/Impact Echo Testing
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Can be conducted on in service or out of service pipe
Requires excavation
Spot testing – 4-6 locations per day
Wall thickness, delaminations, joint conditions
Combine with soil and groundwater testing and pipe wall
soundings and wire investigation
So Many Pipes to Inspect – So Which One’s First?
Acoustic Pulse Testing
• Pipe wall assessment, pipe stiffness and
remaining strength, leak detection
• Conducted on in service pipe
• Excavation only required if hydrants
and valves are absent
• Tests in 150 foot sections (2,500 foot
sections for leak detection only)
• Combine with soil and groundwater
testing and pipe wall soundings and
winding investigation
• Development of failure risk curves
based on results of acoustic stiffness
testing
So Many Pipes to Inspect – So Which One’s First?
Free Swimming Acoustic Leak Detection
(Pure Technologies SmartBall)
Conducted on in service pipe
Excavation only required if 4-inch tap is not available
Travels at 90% of flow rate
Combine with soil and groundwater testing and
pipe wall soundings and winding investigation
• Requires side line valves to be closed
• Data is post-processed requiring return to site to locate leaks
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So Many Pipes to Inspect – So Which One’s First?
DEVELOPMENT OF CAPITAL PLAN
Capital Plan – Summary
Legend
Year 3 Park Avenue 30-inch Main
(Electromagentic Testing and
Leak Detection)
Year 2 30-inch Charles Park Main
(Replacement)
Year 4 Carteret 30-inch Main
(Acoustic Pulse
Testing)
Year 5 Chevron Oil/Florida Grove Road 30-inch Main
(Acoustic Pulse Testing)
Year 7 Woodbridge Ave./Grandview Ave. 30-inch Main
(Acoustic Pulse Testing)
Years 1 and 2 CJO WTP 48-inch
Transmission Main
(Electromagentic Testing and
Acoustical Leak Detection )
Year 6 Main St./Woodbridge Ave. 30”/36”
(Acoustic Pulse Testing)
So Many Pipes to Inspect – So Which One’s First?
Year 8 South River Basin
42-inch Main
(Acoustic Pulse
Testing)
Capital Plan – Year 1 Detailed Plan
So Many Pipes to Inspect – So Which One’s First?
CONCLUSIONS
Conclusion
• Leverage previous investments in technology
– Calculation of potential for and consequence of failure
– Start simply, layer in new factors over time
• Decision framework
– Electronic way of documenting decision points already done by
engineering staff
– But linked to electronic assets in the GIS
– Better tracking, better mapping
– Supports building and tracking real projects in the streets
• Flexible
– Can adjust over time based on other needs
– Graphical and defensible to better support coordination
So Many Pipes to Inspect – So Which One’s First?
Map Criticality – Map and Track Projects
• Output linked to GIS
• Staff can see and build
projects
• Export final decisions to:
– Project tracking system
– Financial systems
• Continuously update
So Many Pipes to Inspect – So Which One’s First?
How to Begin Using the New Approach
• Data barriers can be overcome
– You don’t need complete data on every pipe segment
– There is more data out there than it first appears
– Use the data together for maximum effect
• You need statistics
– Determining and weighting criteria is guesswork without
statistics
– Spot trends you didn’t know about and disprove myths
• Throw out some of the conventional wisdom
– Service life can be as little as 40 or more than 175 years – no
standard
– Traffic loading and soils may be more important than age for
renewal planning
So Many Pipes to Inspect – So Which One’s First?
AMERICAN WATER WORKS ASSOCIATION
NEW JERSEY SECTION
2015 Annual Conference
QUESTIONS??
So Many Pipes to Inspect –
So Which One’s First?
March 19, 2015
David J. Tanzi, P.E., BCEE
CDM Smith
[email protected]
Brian F. Carr, P.E.
Middlesex Water Company
[email protected]
IDDLESEX
ATER COMPANY